266397813 has 12 divisors (see below), whose sum is σ = 419778528. Its totient is φ = 161453160.

The previous prime is 266397779. The next prime is 266397821. The reversal of 266397813 is 318793662.

266397813 is a `hidden beast` number, since 2 + 6 + 639 + 7 + 8 + 1 + 3 = 666.

It is not a de Polignac number, because 266397813 - 2⁹ = 266397301 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (266397013) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1345345 + ... + 1345542.

It is an arithmetic number, because the mean of its divisors is an integer number (34981544).

Almost surely, 2^266397813 is an apocalyptic number.

It is an amenable number.

266397813 is a deficient number, since it is larger than the sum of its proper divisors (153380715).

266397813 is a wasteful number, since it uses less digits than its factorization.

266397813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2690904 (or 2690901 counting only the distinct ones).

The product of its digits is 326592, while the sum is 45.

The square root of 266397813 is about 16321.6976139126. The cubic root of 266397813 is about 643.4432041997.

The spelling of 266397813 in words is "two hundred sixty-six million, three hundred ninety-seven thousand, eight hundred thirteen".